SERVO 09.2014 27
WILLY WONKA GOES ROGUE
Let’s build a quadcopter out of chocolate!
This is exactly what one couple decided to
do. They combined their skills to quench their
curiosity to see if it could be done.
They built a wooden prototype, so they
could create a silicone mold to pour the
chocolate into. They used styrofoam and metal
spacer’s to place in the mold so there would be
spaces left for mounts for the electronics when
the chocolate had set. And yes. It did fly.
MOVE OVER SLINKY,
SQUISHY’S IN TOWN
Most robots are rigid. Rigid is easy to design, easy to
construct, easy to calibrate, and more reliable for all of
those dull, dirty, and dangerous tasks that robots excel at.
When robots make fundamental structural compromises
to rigidity, they do it in complicated ways, like with series
elastic actuators or hydraulics. It's worth it, though,
because adding squishiness can make robots both more
capable and safer to be around through passive
Taking this concept to the extreme has resulted in
some incredibly squishy robots, including ones that can walk and
other ones that can roll. In both of these cases, however,
embracing squishy properties means giving up rigidity. Now, MIT
has been working on a structure for a robot that offers both:
squishy or rigid.
The MIT approach involves taking a material or structure
that's inherently soft and modifying it with another material that
can facilitate change between hard and soft states. In this case,
MIT is using a scaffold made of foam that's been coated with
Wax transitions between solid and liquid at a relatively low
temperature. When the wax is cold and solid, the foam structure
is rigid, but if the wax is heated to soften it, the entire foam
structure becomes soft as well.
The researchers also demonstrated that by selectively
deforming parts of a structure, they could create joints and make
the structure move using a cable. Most likely, these deformable
structures could be combined to create a robot that can crawl
and squeeze into tight spaces.
Wax is one of the easier and safer materials to use for this
purpose, although there are other options like liquid metals or
magnetorheological or electrorheological fluids which respond to
magnetic and electrical fields.
The project began as a collaboration with Boston Dynamics,
as part of DARPA's ChemBot program. The MIT researchers, led
by Anette Hosoi — a professor of mechanical engineering and
applied mathematics — have since teamed up with the Max
Planck Institute for Dynamics and Self-Organization and Stony
Brook University to continue developing versatile deformable
The researchers say that robots like these would be ideal for
search and rescue scenarios where you'd need a lot of
compliance and flexibility for crawling around piles of rubble.
They also suggest that robots like these would be great for
crawling around inside your body where they'd be able to "reach
a particular point without damaging any of the organs or vessels
along the way."
Photo by Hosoi Group/MIT.